Because of their complexity, data processing devices, such as systems on a chip (SOCs) are typically designed using automated design tools, such as a computer-aided design (CAD) system. The CAD system can include automated processes to implement, verify functionality, and improve performance and manufacturability of the data processing device design. To verify functionality, the CAD system simulates input stimuli, such as clock signals, for a data processing device, and simulates the behavior of the device based on the input stimuli. However, verification of functionality can demand an undesirable amount of time, increasing the cost and difficulty of designing the data processing device.